Chickenpox After Vaccine
Chickenpox after vaccine can occur in two different situations. The more common of the two is a breakthrough infection, which is believed to be caused by a wild-type varicella virus. The second situation, in which you catch chickenpox from the chickenpox vaccine itself, is extremely rare. Second-time chickenpox cases are typically very mild.
It is possible to develop chickenpox after getting the chickenpox vaccine. There are two situations where this could occur. The more common of the two is a breakthrough infection. Very rarely, chickenpox can occur from the chickenpox vaccine itself.
No vaccine is 100 percent effective in preventing disease. After vaccination, some people (about 1 person in 10) do not develop enough protection to completely prevent them from developing chickenpox. For the chickenpox vaccine, about 8 to 9 out of every 10 people who are vaccinated are completely protected from chickenpox. The vaccine almost always prevents against severe disease.
If a vaccinated person does get chickenpox, it is called a breakthrough infection. This infection is believed to be caused by a wild-type varicella virus. A breakthrough infection is usually very mild with fewer skin lesions (usually less than 50) lasting only a few days, with no fever or a low fever, and few other chickenpox symptoms. Breakthrough infection is estimated to occur in approximately 2 percent of vaccinations per year. The rate does not appear to increase with length of time since vaccination.
Vaccinated people who get this milder form of chickenpox may still spread the disease to others who are not protected. Therefore, these individuals should stay at home until the blisters have formed scabs; if there are no blisters present, they should stay home until no new spots or bumps are forming.